I smoke. About 1-1/2 pks/day (average-it varies).
Recently went on vacation to the mountains and the chalet we rented
was a no smoking rental. (Surprise!!)
Had to go outside in 17 degree weather, and 20+ mph. winds
(wind chill -minus 7 degrees) to smoke.
I smoked less than 2 pks in the entire week.
No effect on my PN, whatsoever !
(Although I was a nervous wreck the first 2 days.)

I was hospitalized a few years ago, for an unrelated problem.
Spent 2 weeks without a cigarette. No effect on my PN.
No better, no worse.

My mom smoked - Pall Mall unfiltered.
I used to go to the vending machine & buy a pack for her.
Put a quarter in and get a pack with 4 pennies inserted between the
cellophane wrapper and the package wrapper..... 21 cents a pack !!
That was in the late '50's, early 60's. I was born in '44. I'll be 63.

I started smoking when I was about 13-14.
All my life, very good health. No bone breaks....nothing.... ever.
just common childhood things and a cold, occasionally.

Never hospitalized........until 2000. Finally, after 8 years of suffering,
idiot docs & mis-Dx'ng, was D'd with PN. I'd had it for close to 10 years
before it got a name.

I can't say that smoking definitely was a contributing factor - but then again
the reverse could be true as well. But until I can see other than rumor, that smoking is THE factor. Or is a MAJOR factor, I'll do as I wish.

I've come to see that every doctor I've ever talked to, tries to imply that any
ailment is caused by smoking, or smoking is a contributing factor.
I mean any ailment, from bunions to tennis elbow - gets the reply:
"Well if you stopped smoking, it'd be better for your problem"
I realize that the medical profession is on a crusade to eliminate this habit
and addiction for every patient. I realize that it is probably not good for me
but may really not be extremely detrimental (see Mel's landlord) as well.I take umbrage at the fact that my civil rights have been legislated away,
and that I am now deemed to be in a class of undesirable humans.
But I am addicted and do not, at this time, have the desire to become un-addicted.
I did stop once - 20+ yrs ago, and remember what I went thru. I was younger and stronger physically then. I don't relish the thought of going thru that again,
but realize that eventually, I shall............... But just not today.